I have bought a 4G hat for my raspberry pi 3B+ (the sim7600 waveshare for europe) and followed these instructions for setup. It is running the latest version of raspbian and I have internet on the raspberry through the USB interface (wwan0), which works perfectly.
However the next step for me is to setup a wifi hotspot and forward internet to other raspberry pi zeros. I followed setting up hotspot and similar posts like this or this but they all (most) involve ethernet connection. Also, documentation on configuring wwan0 for dhcpcd and dnsmasq or bridging that I could find are not very comprehensive.
I am relatively new and I got stuck in ip table rules and bridges and unable to setup for wwan0. Does somebody know how I should go about this?
*I hope that I have all the relevant configuration files here.
auto lo iface lo inet loopback allow-hotplug wwan0 iface wwan0 inet manual #could not start with static allow hotplug wlan0 iface wlan0 inet manual #same, fails if I substitute with static keyword address 192.168.4.1 netmask 255.255.255.0 network 188.8.131.52 broadcast 184.108.40.206
interface wlan0 static ip_adress=192.168.4.1/24 nohook wpa_supplicant
interface=wlan0 driver=nl80211 ssid=MyId hw_mode=g channel=7 wmm_enabled=1 macaddr_acl=0 auth_algs=1 ignore_broadcast_ssid=0 wpa=2 wpa_key_mgmt=WPA-PSK wpa_passphrase=password wpa_pairwise=TKIP rsn_pairwise=CCMP